RU2660394C2 - Bar force meter with simplified configuration - Google Patents

Abstract

FIELD: meter reading.

SUBSTANCE: present invention relates to a measurement technique and can be used to measure force. Meter containing a rod deformation body, as well as at least four extensometers, which are mounted on the deformation body and are designed to measure the transverse and longitudinal elongation of the deformation body. Front elongated notch is provided on the front side at the intersection point between the central longitudinal axis (L) and the central transverse axis (Q1) of the deformation body. Opposite to the front elongated notch on the rear side is provided a rear elongated recess. On the left side, at least one left upper cutout is provided above the central transverse axis Q1 and one left lower cutout below the center lateral axis Q1. Opposite to these notches, at least one right upper cut and one right lower cut are provided on the right side. Angle α between the central transverse axis Q1 and the shortest connection line V between the front elongated notch and the left upper notch is not less than 17° and not more than 29°.

EFFECT: technical result is to simplify the adjustment of the meter.

21 cl, 15 dwg

Description

This invention relates to a rod force sensor, which provides easier adjustment than the known rod force sensors.

Rod force sensors are known in which the longitudinal elongation and transverse elongation of the deformation body are measured with the aid of the extension sensors installed on the rod measuring body, respectively the deformation body. From the electrical signals generated by the extension sensor, the force to be measured can then be determined. When they are designed to create weights, such force sensors are also called weighing cells.

In a rod-type force transducer of this type, a complex adjustment is required, which is also called rotational adjustment. Due to this, the tolerances of the deformation body or elongation sensors due to the manufacture must be compensated and less sensitivity of the force sensors relative to the effects of lateral or transverse forces and thereby to changes in the input forces should be ensured.

Rotational adjustment is as follows. One end of the rod force transducer is clamped in a holding device. At its other end, the force sensor is loaded with a load device. This process is repeated three more times after the corresponding rotation of the holding device together with the clamped force transducer by 90 °. From the measured values of the force sensor in various rotation positions, it is then determined whether adjustment is necessary. If it is necessary, the sensor is rotated several times again and mechanical adjustment is carried out by means of material removal and / or electrical adjustment. As an alternative solution, the adjustment can also be carried out by turning not the force sensor, but the rotation of the loading device. In this case, for mechanical adjustment, several devices for removing material or a rotary device for removing material are necessary.

Rotational tuning always requires several turns and several loads. Therefore, performing rotational tuning is time consuming.

In EP 0 800 064 B1, a core force sensor of the above kind is explained and the rotational setting performed for it is mentioned. DE 44 16 442 A1 provides a more detailed description of the rotary setting.

Even after such a rotational adjustment, there is a risk of distortion of the measurement result due to the following effect. When a force that is not completely coaxial to the longitudinal axis of a deformation body made in the form of a rod of a deformation body and / or additional transverse forces are applied through the force input surfaces at the end ends of the deformation body, and the deformation body is deformed in the direction across the longitudinal axis, is not uniformly, but one-sided. In other words, the deformation body tilts to one side and is not deformed coaxially with its longitudinal axis, due to which the lines of force no longer pass in the desired way. This leads to a distortion of the measurement results.

Along with rotational adjustment, for example, temperature adjustment is also carried out, so that in the known rod sensors of the force of the above kind it is necessary to carry out several adjustment measures.

From GB 2 162 322 A there is also known a rod force sensor with a cylindrical sedimentary body, on the end surfaces of which the force to be measured is affected. It has two longitudinal holes oriented in the direction of force and lying opposite to each other, the base surfaces of which form a jumper on which strips are placed along and across the direction of force for measuring elongation. The jumper has a through hole in the direction of force in front of and behind the strips for measuring elongation. Due to the two holes, when exposed to force, the lines of force run along the sides next to both holes. Due to this, the distribution of the lines of force in the middle of the sedimentary body, where the strips measuring the elongation are located, is becoming more and more not homogeneous. The jumper zone passes between the elongation measuring strips and the smaller the lines of force, the larger the diameter of the two holes and the smaller the distance from the elongation measuring strips. The sensitivity of the force sensor can be increased by deepening and / or expanding both longitudinal holes. It can be reduced by increasing the diameter of both holes.

In a force transducer described in GB 2 162 322 A, material removal influences the measurement characteristics in order to increase the measuring range with a linear characteristic. In this case, the sensitivity of the force sensor increases by increasing the depth and / or width of the two longitudinal holes, and decreases by increasing the two holes. Thus, a measuring range with a linear characteristic must be very precisely set. This process is iterative and time consuming.

An object of the invention is to provide a force sensor in which mechanical adjustment by means of material removal and / or electrical adjustment is not required to compensate for the deformation due to the manufacture of tolerances in its body or in its elongation sensors, which, however, works linearly and provides very accurate measurement results.

This problem is solved using a force sensor in accordance with the independent claim 1 of the claims. Preferred enhancements to the force sensor are indicated in the dependent claims.

According to paragraph 1 of the claims, the force sensor for measuring the compressive and / or tensile forces comprises a deformation rod body that has at least one front side, one back side, one left side, one right side, one upper end side and one lower end side, and at least four elongation sensors that are mounted on the deformation body and are designed to measure the longitudinal elongation and transverse elongation of the deformation body. An elongated front recess is provided on the front side in the area of the intersection point between the central longitudinal axis and the central transverse axis of the deformation body. Opposite the front elongated recess on the rear side is provided a rear elongated recess. At least one left upper cutout above the central transverse axis and one left lower cutout below the central transverse axis are provided on the left side. Opposite these notches on the left side are provided on the right side at least one right upper notch and one right lower notch. The angle between the central transverse axis and the shortest connecting line between the front elongated notch and the upper left neckline is not less than 17 ° and not more than 29 °.

The special shape of the deformation body with elongated recesses on its front and rear sides, with cutouts on its left and right sides, as well as with a completely defined angle, causes the deformation body to symmetrically lengthen to the left and to the right under the influence of the compressive force to be measured. side. When subjected to the tensile force to be measured, it is contracted, respectively, symmetrically on the left side and on the right side. This is also true when the force acting is not quite coaxial and / or under the influence of additional transverse forces.

Symmetrical deformation is achieved by the fact that between the elongated recesses and cutouts, which are located in a precisely defined way, there remains only a thin bridge. Due to this, a kind of "articulated action" is achieved, which leads to symmetrical deformation. This effect occurs especially clearly when the angle between the central transverse axis and the shortest connecting line is not less than 17 ° and not more than 29 °. This is true regardless of the rated load of the force sensor.

Thus, the force sensor after its manufacture, also without mechanical adjustment by removing material and / or electrical adjustment to compensate for the manufacturing tolerances in the deformation body or elongation sensors, in particular without rotational adjustment, is insensitive to the effects of interfering forces. Due to this, it is possible to abandon labor-consuming adjustment measures, and the force sensor can be easily adjusted. In addition to this, it has high linearity and measurement accuracy, which are completely sufficient under normal requirements for measurement accuracy. This is ensured regardless of the rated load of the force sensor when the above symptoms are present.

According to claim 2, elongated recesses are substantially elliptical.

When the elongated recesses are elliptical or approximately elliptical, they are made completely concave. When the cuts are also made completely concave, then in this case, precisely between the recess and the cutout, there is the thinnest place. This contributes to the symmetrical deformation of the deformation body both when exposed to the compressive force to be measured, and when exposed to the tensile force to be measured. In addition, substantially elliptical elongated recesses can simply be manufactured using a rotationally symmetrical tool.

According to paragraph 3 of the claims, the cutouts are made essentially with the shape of a part of a circle.

When the shape of a part of a circle or approximately the shape of a part of a circle of cutouts, they are made completely concave. When the elongated recesses are also made completely concave, then in this case the thinnest place is exactly between the recess and the notch. This, in turn, favors the symmetrical deformation of the deformation body both when exposed to the compressive force to be measured, and when exposed to the tensile force to be measured. In addition, substantially circularly shaped cutouts can be simply made with a rotationally symmetrical tool.

According to claim 4, the front elongated recess and the rear elongated recess are centered relative to the intersection point. In addition, the left upper neckline and the left lower neckline, as well as the right upper neckline and the right lower neckline, are located symmetrically with respect to the central transverse axis.

The central arrangement of the elongated recesses and the symmetrical arrangement of the cutouts cause the force lines of the compressive force or tensile force to be measured to be uniformly distributed in the deformation body. Due to this, the deformation body is also deformed uniformly.

According to paragraph 5 of the claims, at least four front recesses are provided in the front elongated recesses, and at least four rear recesses are provided in the opposite elongated recess in the opposite case, and this can be through or not through recesses.

Due to the front and rear grooves, the symmetrical deformation of the deformation body is supported in the desired manner.

According to paragraph 6 of the claims, when measuring the force, the ratio between transverse elongation and longitudinal elongation lies between 55% and 72%.

With a ratio between transverse elongation and longitudinal elongation, which is significantly different from the usual ratio between transverse elongation and longitudinal elongation of approximately 30% for force sensors made of metal, such as those specified in EP 0 800 064 B1, are achieved with a special body shape strain, best measurement results.

According to claim 7, at least two front extension sensors are located in the front elongated recess, and at least two rear extension sensors are located in the rear elongated recess. One of the front extension sensors and one of the rear extension sensors are located centrally relative to the intersection point and are designed to measure longitudinal extension. One of the front extension sensors and one of the rear extension sensors relative to the central axis extending orthogonally to the central axis and containing the central transverse axis is not located in the middle and is intended for measuring transverse extension.

By centering the elongation sensors to measure the longitudinal elongation relative to the intersection point, they are located at the place where they provide the best measurement results. The location outside the middle of the elongation sensors for measuring transverse elongation, which may also be located in the wrong place, has less impact on the measured value generated by the force sensor. Their measurement results contribute less to the output measurement value than the measurement results of the elongation sensors for measuring longitudinal elongation.

According to claim 8, at least three front extension sensors are located in the front elongated recess, and at least three rear extension sensors are located in the rear elongated recess. One of the front elongation sensors and one of the rear elongation sensors is centered relative to the point of intersection and is designed to measure longitudinal elongation. Two front extension sensors and two rear extension sensors are located symmetrically with respect to the central transverse axis above and below this axis and are designed to measure lateral extension.

By centering the elongation sensors to measure longitudinal elongation relative to the intersection point, they are each located at the place where they deliver the best measurement results. The symmetrical arrangement of the respective two front and rear extension sensors for measuring lateral extension provides the ability to compensate for their measurement results due to the location not in the middle of these extension sensors.

According to paragraph 9 of the claims, the deformation body is made symmetrical with respect to the formed central longitudinal axis and the central transverse axis of the first plane. In addition, the deformation body in at least one zone in which the front elongated notch, the rear elongated notch and cuts are located is also symmetrical about the second plane passing orthogonally to the central transverse axis and is made symmetrically relative to passing orthogonally to the central longitudinal axis and containing the Central transverse axis of the middle plane.

Basically, the symmetrical execution of the deformation body contributes to its symmetrical deformation.

These metals have material properties and, in particular, Poisson's ratios, which provide the desired deformation characteristics of the deformation body.

The following is a more detailed explanation of the invention with reference to the accompanying drawings, which are schematically depicted:

figa, 1b and 1c is a force sensor 101, according to the first embodiment;

2a, 2b and 2c show a force sensor 201 according to a second embodiment;

figa, 3b and 3c - force sensor 301, according to the third exemplary embodiment;

4a, 4b and 4c show a force sensor 401 according to a fourth embodiment; and

5a, 5b and 5c show a force sensor 501 according to a fifth embodiment.

FIG. 1 a shows a front view of a force sensor 101 according to a first embodiment. FIG. 1b shows a section through a force sensor 101 along a line K-K, and FIG. 1c shows an isometric view of a force sensor 101.

The force sensor 101 comprises a deformation rod body 102 of a material such as, for example, steel, titanium, aluminum, or an alloy of beryllium and copper. It can be made of a rod, for example, a piece of round steel or rectangular steel. The following description assumes that the deformation body is based on a cylindrical rod and has a cylindrical main shape itself, as shown in the figures. However, other embodiments are also possible in which the deformation body 102 may also have more sides than indicated in the following description.

The deformation body 102 has a central longitudinal axis L, which, in the front view shown in FIG. 1a, extends vertically. It also has a first central transverse axis Q1, which is located orthogonally to the central longitudinal axis L and which, in the front view shown in FIG. 1a, extends horizontally. The second central transverse axis Q2 of the deformation body 102, which is located orthogonally to the central longitudinal axis L and the first central transverse axis Q1, extends in the front view of the image plane shown in FIG. 1 a and is shown in FIG. 1 b. The central longitudinal axis L, as well as both central transverse axes Q1 and Q2, all pass through a common intersection point S and are orthogonal to each other. They form three planes that also extend orthogonally to each other. The force sensor 101 and its deformation body 102 are substantially symmetrical about each of the three planes formed by the central longitudinal axis L, as well as the two central transverse axes Q1 and Q2, as will be explained in more detail below.

The deformation body 102 has a front side 103, which is shown frontally in the front view shown in FIG. It also has the back side 104 shown in FIG. 1 a, which is shown in FIG. 1 b at least in cross section. It is symmetrical to the front side shown in FIG. 1a and also looks when viewed from the front. In other words, FIG. 1 a could also show the rear side 104 frontally, only with a different designation. In addition, the deformation body 102 has a left side 105 in FIG. 1a, a right side 106 in FIG. 1a, a right end side 107 in FIG. 1a, and a lower end side 108 in FIG. 1a.

The upper end side 107 and the lower end side 108 form each force input surface through which the force F to be measured can be introduced, respectively, the corresponding opposite force. The upper end side 107 and the lower end side 108 are preferably spherical and centered relative to the central longitudinal axis L. However, the upper end side 107 and the lower end side 108 can be made flat. In addition, both the upper end side 107 and the lower end side 108 can be made flat.

As shown in FIG. 1b, and especially in FIG. 1c, in the manufacture of the deformation body 102 from the cylindrical rod that makes up its base, material is removed in its longitudinal longitudinal front and rear region, so that the front side 103 and the rear side 104 in its middle zone is made flattened, respectively, flat. At the upper and lower end of the deformation body 102, a cylindrical basic shape is retained, however, the diameter varies in several steps, as will be explained below.

As shown in particular in FIGS. 1a and 1c, the deformation body 102 has on its front side 103 a front elongated recess 109, which extends in the direction passing through the upper end side 107 and the lower end side 108 of the central longitudinal axis L of the deformation body 102 in flattened area of the front side 103. It has at its upper end and at its lower end a considerable distance to the edge of the flattened area of the front side 103, while at its left end and at its right end it ends near this edge. In other words, the main axis of the front elongated recess 109 extends in the direction of the central longitudinal axis L, and its side axis extends in the direction of the first central transverse axis Q1, while its main vertices form its upper and lower end, and its side vertices form its left and right end.

On its rear side 104, the deformation body 102 has a rear elongated recess 110, which is not fully visible in the drawing, but shown in FIG. 1b at least in cross section. It lies opposite the front elongated recess 109, has the same shape and is located in the flattened area of the rear side 104. In other words, the rear elongated recess 110 could also be shown in FIGS. 1a and 1c, but with a different designation.

Both elongated recesses 109 and 110 are each located in the middle of the deformation body 102, i.e. in the region of the intersection point S between the central longitudinal axis L extending from the left side 105 to the right side 106 of the first transverse axis Q1 and passing from the front side 103 to the rear side 104 of the second transverse axis Q2. More specifically, both elongated recesses 109 and 110 are centered about the intersection point S. Each of the elongated recesses 109 and 110 is preferably elliptical. However, other elongated shapes are also possible, such as, for example, the shape of the elongated hole or the shape indicated in connection with the fifth exemplary embodiment.

As shown in FIG. 1b, between the front elongated recess 109 and the rear elongated recess 110, a middle jumper 111 remains on which elongation sensors are applied, as will be explained below. The main surface at the lower end of the front elongated recess 109 and the main surface at the lower end of the rear elongated recess 110, which form the corresponding side of the middle web 111, are preferably plane parallel.

The depth of the elongated recesses 109 and 110 and thereby the thickness d of the jumper 111 remaining between them are selected depending on the nominal load for which the force sensor 101 is intended. The first embodiment is based on a relatively small nominal force, such as, for example, 7,500 kg, so that the thickness d of the middle web 111 in this case is relatively small. At higher nominal loads, the thickness d is correspondingly larger in order to fulfill the high stability requirements of the deformation body 102.

As shown in FIGS. 1 a and 1 c, the deformation body 102 has on its left side 105 a left upper groove, respectively, a cut 112 that is above the first central transverse axis Q1, and a left lower groove, respectively, a cut 103, which is under the first the central transverse axis Q1. In addition, on the right side 106 of the deformation body 102, a right upper groove, respectively, a notch 114, which is located above the first central transverse axis Q1 and lies opposite the left upper notch 112, and a lower right groove, respectively, a notch 115, which is under the first the central transverse axis Q1 and lies opposite to the lower left notch 113. Also possible with more than two notches on each side.

The left cutouts 112 and 113 have both the same distance to the first central transverse axis Q1, respectively, to the plane formed by it and the second central transverse axis Q2, i.e. they are located symmetrically with respect to the first central transverse axis Q1, respectively, of this plane. The same is true for the right cutouts 114 and 115. Each of the cutouts 112, 113, 114 and 115 is preferably made in the form of a part of a circle, but may also have a different shape, for example, part of an ellipse. In the force sensor 101, according to the first exemplary embodiment, each of the cutouts 112, 113, 114 and 115 extends into the flattened area of the front side 103 and into the flattened area of the rear side 104.

Between the front elongated recess 109 and the cutouts 112, 113, 114 and 115, there remains, as well as between the rear elongated recess 110 and the cutouts 112, 113, 114 and 115, the corresponding jumper, which in its thinnest place has a width b. This is shown in FIG. 1a as an example for the front elongated recess 109, the left upper recess 112 and the bridge 116 therebetween, however, based on the generally symmetrical design of the deformation body 102, it is also true for the other recesses 113, 114 and 115, and also for the rear elongated recess 110. In other words, between the front elongated recess 109 and each of the cutouts 112, 113, 114 and 115 there is a jumper, which in its thinnest place has a width b.

When the front elongated recess 109 and the rear elongated recess 110 are made strictly concave, respectively, concave along the entire length, i.e., for example, as mentioned above, have an elliptical shape, and also the cutouts 112, 113, 114 and 115 are made strictly concave, respectively, concave along the entire length, i.e., for example, as mentioned above, have the shape of a part of a circle, then between one of the elongated recesses 109 and 110, as well as one of the cutouts 112, 113, 114 and 115 there is exactly one thinnest the place where the corresponding jumper has a width b. Thus, there is exactly one shortest connection line with a length l, which is equal to the width b of the bridge, between the elongated recess and the notch. For example, as shown in figa, there is a shortest connecting line V with a length l between the front elongated recess 109 and the left upper neckline 112.

The angle α between the first central transverse axis Q1 and the shortest connecting line V with a length l between the front elongated recess 109 and the left upper neckline 112, respectively, the continuation of this shortest connecting line V, as shown in figa, is between 17 ° and 29 ° , i.e. not less than 17 ° and not more than 29 °. Based on the generally symmetrical design of the deformation body 102, this is also true, respectively, for the rear elongated recess 110, as well as for other cutouts 113, 114, and 115.

On the front side 103 of the deformation body 102, as shown in FIGS. 1 a and 1 c, a front middle extensometer 117, a front upper extensometer 118 and a front lower extensometer 119 are installed, which can be implemented on one common medium or on separate carriers. Figures 1a and 1c show an embodiment with one common front carrier 120. The common carrier provides the advantages indicated in EP 0 800 064 B1, such as, for example, low manufacturing costs, low connection costs and simplified installation.

The common front carrier 120, respectively, the front extension sensors 117, 118 and 119 are located in the front elongated recess 109. The front middle extensometer 117 is designed to measure the longitudinal elongation of the deformation body 102 in the direction of the central longitudinal axis L and is centered relative to the intersection point S. In contrast, the front upper extensometer 118 and the front lower extensometer 119 are designed to measure the lateral elongation of the deformation body 102 arising in the direction of the first central transverse axis Q1, are centered relative to the central longitudinal axis L and symmetrically with respect to the first central transverse axis Q1, respectively, formed by it and the second central transverse axis Q2 of the plane, i.e. at an equal distance to them, above and below the first central transverse axis Q1, respectively, of this plane.

On the rear side 104 of the deformation body 102, a rear middle extensometer 121, a rear upper extensometer 122 and a rear lower extensometer 123 are installed, which are not visible in FIGS. 1a and 1c and are only partially visible in FIG. 1b. They correspond to front extension sensors 117, 118 and 119 and lie, respectively, opposite to them. They can also be implemented on one common carrier or on separate carriers, using the rear common carrier 124. not visible in FIGS. 1a and 1c and visible in cross section in FIG. 1b. Accordingly, in FIGS. 1a and 1c could also be shown three rear sensors 121, 122 and 123 of the extension, as well as their common rear carrier 124, indicated by other positions.

Thus, the common rear carrier 124, respectively, the rear sensors 121, 122 and 123 are located in the rear elongated recess 110 and opposite the front common carrier 120, respectively, of the front extension sensors 117, 118 and 119. The rear center extensometer 121, as well as the front center extensometer 117, is designed to measure the longitudinal elongation of the deformation body 102 in the direction of the central longitudinal axis L and is centered relative to the intersection point S. In contrast, the rear upper extensometer 122 and the rear lower extensometer 123, as well as the front extension sensors 118 and 119, are designed for the transverse extension occurring in the direction of the first central transverse axis Q1, are centered relative to the central longitudinal axis L and symmetrically with respect to the first central transverse axis Q1, respectively, formed by it and the second central transverse axis Q2 of the plane, i.e. at the same distance to them, above and below the first central transverse axis Q1, respectively, of this plane.

Sensors 117, 118, 119, 121, 122 and 123 may be, for example, electrical or optical extension sensors. So, for example, front extension sensors 117, 118 and 119 can be implemented in the form of three measuring gratings on the film of the film measuring strip extension, as well as rear extension sensors 121, 122 and 123 can be implemented in the form of three measuring gratings on the film of another film measuring elongation strips, or all elongation sensors can be implemented in the form of a Bragg grating of optical strips measuring elongation.

A different number of extension sensors may also be provided. So, for example, only one elongation sensor for measuring longitudinal elongation and one elongation sensor for measuring transverse elongation can be installed on both the front side and the rear side 104, as described in EP 0 800 064 B1. Extension sensors can be connected to each other at the Wheatstone bridge. In addition, certain electronic components may be provided for further processing of the signal extension provided by the sensors, such as, for example, amplifiers, analog-to-digital converters, etc., while they can also be implemented as parts of an integrated circuit.

When the force sensor 101 is used to measure the input force F, i.e. when measuring the force, the ratio between the measured elongation sensors 117, 118, 119, 121, 122 and 123 of the transverse extension and the longitudinal extension of the deformation body 102 lies between 55% and 72%.

As shown in figa and 1C, in the front elongated recess 109 there are four front recesses 125 ', 125' ', 125' '' and 125 '' '', which are hereinafter referred to together as front recesses 125. The first front recess 125 ' and the second front recess 125 ″ are located above the front extension sensors 117, 118 and 119, respectively, above the front common carrier 120 and have both the same distance to the central longitudinal axis L, respectively, formed by it and the second central transverse axis Q2 of the plane, i.e. e. they are located symmetrically with respect to the central longitudinal axis L, respectively, of this plane. The third front recess 125 ″ ″ and the fourth front recess 125 ″ ″ are located below the front extension sensors 117, 118 and 119, respectively, below the front common carrier 120 and have both the same distance from the central longitudinal axis L, respectively, formed by it and the second central transverse axis Q2 of the plane, i.e. they are located symmetrically with respect to the central longitudinal axis L, respectively, of this plane.

The first front recess 125 'and the second front recess 125' '' on the one side, as well as the third front recess 125 '' 'and the fourth front recess 125' '' 'on the other side, are additionally the same distance from the first central transverse axis Q1, respectively, the plane formed by it and the second central transverse axis Q2, i.e. they are located symmetrically with respect to the first central transverse axis Q1, respectively, of this plane.

Four rear recesses 126 ′, 126 ″, 126 ″ ″ and 126 ″ ″ are provided in the rear elongated recess 110, which are not shown in the figures and are hereinafter referred to together as the rear recesses 126. They lie opposite to the four front recesses 125 and have the same form with them. In other words, four back recesses 126 could also be shown in FIGS. 1a and 1c and are indicated by other positions.

The four front recesses 125 may be end-to-end recesses, in which case they coincide with the four rear recesses 126, i.e. are identical. The four front recesses 125 and the four rear recesses 126 may also be non-through recesses, in which case material remains between the main surfaces at the lower ends of the opposing recesses. This is implemented in the force sensor 101 according to the first embodiment.

The four front recesses 125 and the four rear recesses 126 may have a circular cross section, as shown in FIGS. 1a and 1c, but may also have, for example, an elliptical cross section, made in the form of elongated holes, or have other shapes. Additionally, more or less than four recesses can be provided, and the recesses can also be positioned differently than in FIGS. 1a and 1c.

At the upper and lower end of the deformation body 102, it is in transition from the flattened area of the front side 103, respectively, of the rear side 104 to the area in which the cylindrical main shape is retained, first a circumferential narrow upper protrusion 127, respectively, a circular narrow lower protrusion 128, the diameter of which slightly larger than the distance from the left side 105 to the right side 106, and the diameter of the deformation body 102 immediately after the protrusions 127 and 128, which is preferably equal to this distance. Then the upper first section 129, respectively, the lower first section 130 with this diameter and the upper second section 131, respectively, the lower second section 132 with a smaller diameter, respectively, the upper second section 131 at its upper end ends with the upper end side 107, respectively, a force input surface formed by the upper end side 107, and the lower second portion 132 at its lower end ends with the rear end face 108, respectively, formed by the upper face end 108 of the force input surface.

In the upper second portion 131 for connection with a force input device, such as, for example, a weighing platform, with which force F to be measured can be introduced, as shown in figa and 1c, a thread 133 is made, or another fastener not shown means, such as, for example, a transverse hole. In the lower second portion 132 for connection to a force input device, such as, for example, a weighing platform, with which force F to be measured can be introduced, as shown in FIGS. 1a and 1c, a thread 134 is made, or another fastener not shown means, such as, for example, a transverse hole.

A through hole 135 can be provided in the upper first portion 129, which begins horizontally, then slopes downward, and finally, beneath the lower upper protrusion 127 ends in the upper region of the upper right cutout 114. It serves to pass a cable not shown, with which it can extension sensors 117, 118, 119, 121, 122 and 123, or electronic components included behind them, should be connected. Thus, the sensors 117, 118, 119, 121, 122 and 123 or electronic components can be connected, for example, to an evaluation device and / or an indication device, even when they are hermetically sealed to protect against dust, moisture or other environmental influences. In this case, the sealing can be realized, for example, using a circle-closed sleeve, which extends along the central longitudinal axis L as far as the flattened area of the front side 103, respectively, of the rear side 104.

Fig. 2a shows a front view of the force sensor 201 according to the second embodiment, Fig. 2b is a sectional view of the force sensor 201 along the line K-K, and Fig. 2c is a perspective view of the force sensor 201.

Elements 202-224 and 227-235 correspond, with the exception of the following modifications, indicated in connection with the first exemplary embodiment to elements 102-124 and 127-135, while the force sensor 201, according to the second embodiment, does not have front recesses 125 and rear recesses 126 elements. The modifications are due to the fact that in the second embodiment, the nominal load is increased, for example, to 15,000 kg.

As shown in FIGS. 2a, 2b and 2c, the elongated recesses 209 and 210 are slightly narrower than the elongated recesses 109 and 110, which also applies to flattened areas of the front side 203 and the rear side 204. The thickness d of the middle web 211 is somewhat more than the width of the middle bridge 111. The elongated recesses 209 and 210 each have at their upper end and at their lower end a significant distance to the edge of the flattened area of the front side 203, respectively, of the rear side 204, however, almost at their left end and at their right end to this edge.

The cutouts 212, 213, 214 and 215 are made somewhat less deep than the cutouts 112, 113, 114 and 115 and extend to the edge of the flattened area of the front side 203 and to the edge of the flattened area of the rear side 204.

FIG. 3 a shows a front view of a force sensor 301 according to a third embodiment, FIG. 3 b shows a section through a force sensor 301 along line K-K, and FIG. 3 c shows a force sensor 301 in isometric view.

Elements 302-332 and 335 correspond, with the exception of the following modifications, indicated in connection with the first exemplary embodiment to elements 102-132 and 135, while in the force sensor 301, according to the third embodiment, the corresponding upper threads 133 and lower carving 134 elements. The modifications are due to the fact that in the third embodiment, the nominal load is increased, for example, to 20,000 kg.

As shown in figa, 3b and 3C, the elongated recesses 309 and 310 are made narrower than the elongated recesses 109 and 110, which also applies to flattened areas of the front side 303 and the rear side 304. The thickness d of the middle bridge 311 is greater the width of the middle lintel 111. The elongated recesses 309 and 310 each have at their upper end and at their lower end a considerable distance to the edge of the flattened area of the front side 303, respectively, of the rear side 304, however, before its left end and its right end the edges.

The cutouts 312, 313, 314 and 315 are made deeper and with a smaller radius than the cutouts 112, 113, 114 and 115, however, also extend into the flattened area of the front side 303 and the flattened area of the rear side 304.

The four front recesses 325 are through recesses and coincide with the rear recesses 326, respectively, identical to them.

Fig. 4a shows a front view of the force sensor 401 according to the third exemplary embodiment, Fig. 4b is a sectional view of the force sensor 401 along the line K-K, and in Fig. 4c, the force sensor 401 is shown in isometric view.

Elements 402-432 and 435 correspond, with the exception of the following modifications, indicated in connection with the first exemplary embodiment to elements 102-132 and 135, while in the force sensor 401, according to the fourth embodiment, the corresponding upper threads 133 and lower carving 134 elements. The modifications are due to the fact that in the fourth embodiment, the nominal load is increased, for example, to 30,000 kg.

As shown in figa, 4b and 4C, the elongated recesses 409 and 410 are made much narrower than the elongated recesses 109 and 110, which also applies to flattened areas of the front side 403 and rear side 404. The thickness d of the middle bridge 411 significantly larger than the width of the middle lintel 111. The elongated recesses 409 and 410 each have at their upper end and at their lower end a considerable distance to the edge of the flattened area of the front side 403, respectively, of the rear side 404, however, at their left end and at their right end before the edges.

The cutouts 412, 413, 414 and 415 are made deeper and with a smaller radius than the cutouts 112, 113, 114 and 115. They each extend not quite to the flattened area of the front side 403 and to the flattened area of the rear side 404.

In the front elongated recesses 409 there are six front recesses 425 ', 425' ', 425' '', 425 '' '', 425 '' '' '' and 245 '' '' '', which are hereinafter referred to collectively as the front recesses 425 The four front recesses 425 ', 425' ', 425' '' 'and 425' '' '' correspond to the four front recesses 125 ', 125' ', 125' '' 'and 125' '' '. The fifth front recess 425 ″ ″ ″ is located above the first front recess 425 ″ and the second front recess 425 ″, and also centered relative to the central longitudinal axis L. The sixth front recess 425 ″ ″ ″ ″ is located under the third front recess 425 ″ '' and the fourth front recess 425 '' '', and also centered relative to the central longitudinal axis L. The six front recesses 425 are each through recesses and coincide with the six rear recesses 426, respectively, identical to them.

Fig. 5a shows a front view of the force sensor 501 according to the fifth exemplary embodiment, Fig. 5b is a sectional view of the force sensor 501 along the line K-K, and Fig. 5c shows a force sensor 501 in isometric view.

The force sensor 501, according to the fifth embodiment, is similar to the force sensor 101, according to the first embodiment. Elements 502-508 and 511-535 correspond to those indicated in connection with the first exemplary embodiment, elements 102-108 and 111-135. Only elongated recesses 509 and 510 are made different from elongated recesses 109 and 110.

As shown in FIGS. 2a and 5c, the elongated recesses 509 and 510 at their upper end and at their lower end expand once more. Due to this, the edges of the cutouts 512, 513, 514 and 515 and the edges of the elongated recesses 509 and 510 extend parallel to one segment, and this is not the thinnest place, but the thinnest zone with a width d in which there is a corresponding jumper between the recess and the cut . Thus, there is not exactly one shortest connection line with a length l, which is equal to the width b of the bridge, between the elongated recess and the notch. Therefore, in this case, to determine the angle α, the shortest connection line that passes through the middle of the thinnest zone with width b is relevant. This is shown in FIG. 5a for the shortest connection line V with a length l between the front elongated recess 509 and the left upper cutout 512.

As long as the edges of the cutouts 512, 513, 514 and 515 and the elongated recesses 509 and 510 extend only parallel to a short segment, and thus the thinnest zone with a width b in the corresponding jumper between the recess and the cutout is small, then when the angle α is not less than 17 ° and not more than 29 °, the same positive effects occur as in other examples.

The shape of the elongated indentations 509 and 510 is one of many possible alternatives to the fully elliptical shape of the elongated indentations. Moreover, these alternatives can be based not only on the first example of execution, but also on the second, third or fourth example of execution.

Other modifications of sensors 101-501 are possible, according to the first to fifth embodiment. So, for example, in the force sensor 101, according to the first exemplary embodiment, elements corresponding to the front recesses 125 and the rear recesses 126 may be provided, which may be through or not through notches. In addition to this, in all examples of execution, a different number of front and rear recesses is possible.

In addition, for example, in the force sensor 301, according to the third exemplary embodiment, and in the force sensor 401, according to the fourth exemplary embodiment, elements corresponding to the upper thread 133 and the lower thread 134 or other fixing means may be provided. Also, force sensors, according to other exemplary embodiments, can be performed without such a thread or fastening means.

In addition, numerous modifications of the above force sensors are possible, in particular with respect to the explained elements of these force sensors.

Thus, the present invention relates to a force sensor for measuring compression and / or tensile forces, which has a rod body of deformation with at least one front side, one back side, one left side, one right side, one upper end side and one lower end face, as well as with at least four elongation sensors that are mounted on the deformation body and are designed to measure the transverse elongation and longitudinal elongation of the deformation body. An elongated front recess is provided on the front side in the area of the intersection point between the central longitudinal axis and the central transverse axis of the deformation body. Opposite the front elongated recess on the rear side is provided a rear elongated recess. At least one left upper cutout above the central transverse axis and one left lower cutout below the central transverse axis are provided on the left side. Opposite these notches on the left side are provided on the right side at least one right upper notch and one right lower notch. The angle between the central transverse axis and the shortest connection line between the front elongated notch and the upper left notch is not less than 17 ° and not more than 29 °.

The force sensor can also work with high linearity without mechanical adjustment by removing material and / or electrical adjustment to compensate for the manufacturing tolerances in the deformation body or elongation sensors and deliver very accurate measurement results.

Claims (51)

1. A force sensor (101; 201; 301; 401; 501) for measuring compression and / or tensile forces, comprising a rod body (102; 202; 302; 402; 502) of deformation, which has at least one front side (103; 203; 303; 403; 503), one back side (104; 204; 304; 404; 504), one left side (105; 205; 305; 405; 505), one right side (106; 206; 306; 406; 506), one upper end side (107; 207; 307; 407; 507) and one lower end side (108; 208; 308; 408; 508); and at least four extensometers (117, 118, 119, 121, 122, 123; 217, 218, 219, 221, 222, 223; 317, 318, 319, 321, 322, 323; 417, 418, 419, 421, 422, 423; 517, 518, 519, 521, 522, 523), which are installed on the body (102; 202; 302; 402; 502) deformations and are designed to measure the transverse elongation and longitudinal elongation of the body (102; 202; 302; 402; 502) deformations, while on the front side (103; 203; 303; 403; 503) there is a front elongated notch (109; 209; 309; 409; 509) in the area of the point of intersection (S) between the central longitudinal axis (L) and the central transverse axis (Q1) body (102; 202; 302; 402; 502) deformations, and opposite to it on the back side (104; 204; 304; 404; 504) there is a rear elongated notch (110; 210; 310; 410; 510), on the left side (105; 205; 305; 405; 505) there are at least one upper left neckline (112; 212; 312; 412; 512) above the central transverse axis (Q1) and one left lower neckline (113; 213; 313; 413; 513) under the central transverse axis (Q1), as well as opposite to them, are provided on the right side (106; 206; 306; 406; 506) at least one upper right neckline (114; 214; 314; 414; 514 ) and one right lower neckline (115; 215; 315; 415; 515), the angle (α) between the central transverse axis (Q1) and the shortest line (V) of the connection between the front elongated notch (109; 209; 309; 409; 509) and the upper left neckline (112; 212; 312; 412; 512) is not less 17 ° and not more than 29 °. 2. The force sensor (101; 201; 301; 401; 501) according to claim 1, wherein the elongated recess (109, 110; 209, 210; 309, 310; 409, 410; 509, 510) is made essentially elliptical in shape . 3. The force sensor (101; 201; 301; 401; 501) according to claim 1 or 2, wherein the cutouts (112, 113, 114, 115; 212, 213, 214, 215; 312, 313, 314, 315; 412, 413, 414, 415; 512, 513, 514, 515) are made substantially in the form of part of a circle. 4. The sensor (101; 201; 301; 401; 501) of the force according to claim 1 or 2, in which the front elongated notch (109; 209; 309; 409; 509) and the rear elongated notch (110; 210; 310; 410; 510) are each centered relative to the intersection point (S), and the upper left neckline (112; 212; 312; 412; 512) and the lower left neckline (113; 213; 313; 413; 513), as well as the upper right neckline (114; 214; 314; 414; 514) are each symmetrically located central transverse axis (Q1). 5. The sensor (101; 201; 301; 401; 501) of force according to claim 3, in which the front elongated notch (109; 209; 309; 409; 509) and the rear elongated notch (110; 210; 310; 410; 510) are each centered relative to the intersection point (S), and the upper left neckline (112; 212; 312; 412; 512) and the lower left neckline (113; 213; 313; 413; 513), as well as the upper right neckline (114; 214; 314; 414; 514) are each symmetrically located central transverse axis (Q1). 6. The sensor (101; 201; 301; 401; 501) of the force according to claim 1 or 2, in which in the front elongated notch (109; 209; 309; 409; 509), at least four front notches (125; 225; 325; 425; 525) are provided and, accordingly, opposite to them in the rear elongated notch (110; 210; 310; 410; 510) at least four rear recesses (126; 226; 326; 426; 526) are provided, while they may be through or not through notches. 7. The sensor (101; 201; 301; 401; 501) of force according to claim 3, in which in the front elongated notch (109; 209; 309; 409; 509), at least four front notches (125; 225; 325; 425; 525) are provided and, accordingly, opposite to them in the rear elongated notch (110; 210; 310; 410; 510) at least four rear recesses (126; 226; 326; 426; 526) are provided, while they may be through or not through notches. 8. The sensor (101; 201; 301; 401; 501) of force according to claim 4, in which in the front elongated notch (109; 209; 309; 409; 509), at least four front notches (125; 225; 325; 425; 525) are provided and, accordingly, opposite to them in the rear elongated notch (110; 210; 310; 410; 510) at least four rear recesses (126; 226; 326; 426; 526) are provided, while they may be through or not through notches. 9. The sensor (101; 201; 301; 401; 501) of force according to claim 5, in which in the front elongated notch (109; 209; 309; 409; 509), at least four front notches (125; 225; 325; 425; 525) are provided and, accordingly, opposite to them in the rear elongated notch (110; 210; 310; 410; 510) at least four rear recesses (126; 226; 326; 426; 526) are provided, while they may be through or not through notches. 10. The sensor (101; 201; 301; 401; 501) of the force according to claim 1 or 2, in which when measuring force, the ratio between transverse elongation and longitudinal elongation lies between 55% and 72%. 11. The sensor (101; 201; 301; 401; 501) of force according to claim 3, in which when measuring force, the ratio between transverse elongation and longitudinal elongation lies between 55% and 72%. 12. The sensor (101; 201; 301; 401; 501) of force according to claim 4, in which when measuring force, the ratio between transverse elongation and longitudinal elongation lies between 55% and 72%. 13. The sensor (101; 201; 301; 401; 501) of force according to claim 5, in which when measuring force, the ratio between transverse elongation and longitudinal elongation lies between 55% and 72%. 14. The sensor (101; 201; 301; 401; 501) of force according to claim 6, in which when measuring force, the ratio between transverse elongation and longitudinal elongation lies between 55% and 72%. 15. The sensor (101; 201; 301; 401; 501) of force according to claim 7, in which when measuring force, the ratio between transverse elongation and longitudinal elongation lies between 55% and 72%. 16. The sensor (101; 201; 301; 401; 501) of force according to claim 8, in which when measuring force, the ratio between transverse elongation and longitudinal elongation lies between 55% and 72%. 17. The force sensor (101; 201; 301; 401; 501) according to claim 9, wherein when measuring force, the ratio between transverse elongation and longitudinal elongation lies between 55% and 72%. 18. The sensor (101; 201; 301; 401; 501) of the force according to claim 1 or 2, in which at least two front extensometers (117, 118, 119; 217, 218, 219; 317, 318, 319; 417, 418, 419; 517, 518 are located in the front elongated notch (109; 209; 309; 409; 509) , 519), and in the rear elongated notch (110; 210; 310; 410; 510) there are at least two rear extensometers (121, 122, 123; 221, 222, 223; 321, 322, 323; 421, 422, 423; 521, 522, 523), one of the front extensometers (117; 217; 317; 417; 517) and one of the rear extensometers (121; 221; 321; 421; 521) are centered relative to the intersection point (S) and are designed to measure longitudinal elongation, and one of the front sensors (118; 218; 318; 418; 518) and one of the rear extensometers (122; 222; 322; 422; 522) is located not in the middle relative to the orthogonal central longitudinal axis (L) and containing the central transverse axis (Q1 ) the middle plane and is designed to measure lateral elongation. 19. The sensor (101; 201; 301; 401; 501) of the force according to claim 1 or 2, in which at least three front extensometers (117, 118, 119; 217, 218, 219; 317, 318, 319; 417, 418, 419; 517, 518 are located in the front elongated notch (109; 209; 309; 409; 509) , 519), and in the rear elongated recess (110; 210; 310; 410; 510) there are at least three rear extensometers (121, 122, 123; 221, 222, 223; 321, 322, 323; 421, 422, 423; 521, 522, 523), one of the front extensometers (117; 217; 317; 417; 517) and one of the rear extensometers (121; 221; 321; 421; 521) are centered relative to the intersection point (S) and are designed to measure longitudinal elongation, and two front extensometers (118, 119; 218, 219; 318, 319; 418, 419; 518, 519) and two rear extensometers (122, 123; 222, 223; 322, 323; 422, 423; 522, 523) are located symmetrically with respect to the central transverse axis (Q1) above and below it and are intended for measuring transverse elongation. 20. The sensor (101; 201; 301; 401; 501) of the force according to claim 1 or 2, in which the deformation body (102; 202; 302; 402; 502) is symmetrical about the first plane formed by the central longitudinal axis (L) and the central transverse axis (Q1), and a deformation body (102; 202; 302; 402; 502) in at least one zone in which there is a front elongated notch (109; 209; 309; 409; 509), a rear elongated notch (110; 210; 310; 410; 510) and cutouts (112, 113, 114, 115; 212, 213, 214, 215; 312, 313, 314, 315; 412, 413, 414, 415; 512, 513, 514, 515), performed symmetrically also with respect to the second plane passing orthogonally to the central transverse axis (Q1) and containing the central longitudinal axis (L), and is symmetrical to the middle plane passing orthogonally to the central longitudinal axis (L) and containing the central transverse axis (Q1). 21. The sensor (101; 201; 301; 401; 501) of the force according to claim 1 or 2, in which the body (102; 202; 302; 402; 502) of the deformation consists of steel, titanium, aluminum, or an alloy of beryllium and copper.

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